AIM: To investigate the efficacy of unilateral medial rectus resection in children with residual and recurrent exotropia and analyze the influence of difference types of strabismus and methods of primary surgery on the surgical outcome.

METHODS:This investigation was a retrospective case series study that examined data from 48 pediatric patients(48 eyes)who underwent unilateral medial rectus resection between January 2009 and February 2013 for residual and recurrent exotropia. We surveyed the outcome of eye alignment, lateral incomitance, fusion function, stereoacuity in children at 1d, 6wk and at last follow-up of 6-32(mean 11.99±7.06)mo after the surgery.

RESULTS: At 1d after the surgery, the rate of surgical success was 83%(40/48), and the rate of undercorrection and overcorrection was 4%(2/48)and 13%(6/48), respectively. At 6wk after the surgery, the rate of surgical success was 81%(39/48), and the rate of undercorrection and overcorrection was 13%(6/48)and 6%(3/48), respectively. At the final follow-up of 6-32(mean 11.99±7.06)mo, the surgical success rate was 75%(36/48), and the rate of undercorrection was 25%(12/48). No patient exhibited overcorrection. There were no significant differences in the surgical success rate either among pediatric patients who had previously undergone different types of surgery or among patients who had been diagnosed with different types of exotropia(P=0.168 and P=0.50, respectively). No patients presented with lateral incomitance or limited ocular motility.

CONCLUSION: Unilateral medial rectus resection is a safe and effective surgical approach for treating in children with residual and recurrent exotropia. In addition, it may achieve the same surgical effectiveness regardless of the patients' previous surgical procedures or types of exotropia.